Pretreatment Experiment Of Soybean Extrusion Used In Solvent Extraction Of Oil And The Visualization Study On The Processing Of Soybean Extruded

In this paper, the pre-treatment of expanding extraction was adopted, which obtained the nationality patent (patent number: 98115743.2), i.e., the soybean meal only needs cleaning, crashing, expanding and extracting. The test method of second power, revolving, orthogonal and tropical design of four factors and five levels and the data processor named Reda was adopted. The effects of extrusion-expanding pre-treatment on the indexes of swelling degree of the extruded meals, the shearing strength of the extruded meals, the residual oil rate and the Nitrogen Solubility Index(NSI) in the meals were systematically analyzed. First, the soybean powder was extruded by a single screw extruder. About 40 minutes later, measured the swelling degree and shearing strength of the extruded meals and extracted the extruded meals about 110 minutes when the extracted temperature was 57℃. The last, detected the residual oil rate and the Nitrogen Solubility Index in the meal.The Principle of high velocity camera was studied and the process of extrusion was shot with high velocity camera. The change of state and the kinematical parameter of the material particles in the extruder were systematically analyzed.In the respect of pre-treatment of expanding extraction:The mono factorial experiments on new factors were carried out, including the diameter of the choked flow loops, the speed of feeding.The principal of the influence of parameters of extrusion system on the residual oil rate in the extracted meal was studied. Mathematical relationship was established between the parameters of extrusion system and the residual oil rate in the meal.The principal of the influence of parameters of extrusion system on the NSI of soybean meal was studied. Mathematical relationship was established between the parameters of extrusion system and the NSI in the extracted meal.The principal of the influence of parameters of extrusion system on the swelling degree of the extruded meals was studied. Mathematical relationship was established between the parameters of extrusion system and the swelling degree of the extruded meal.The principal of the influence of parameters of extrusion system on the shearing strength of the extruded meals was studied. Mathematical relationship was established between the parameters of extrusion system and the shearing strength of the extruded meal.The parameters of extrusion system that could obtain the extruded meals having the lower residual oil rate and higher NSI and the relation between residual oil rate in meal and swelling degree of extruded meal were systematically analyzed.In the respect of visualization experiments:The Principle of high-speed photography was studied. The high-speed photography system corresponding to actual needs and regulations on environmental demand was established.In the base of visualization experiments, the process of soy extrusion was divided three stages: solid transportation stage, meltdown stage and melting mass transportation stage.The kinematical parameters of the material particles in the extruder were systematically analyzed. The soybean powder in solid transportation stage was transported at particle form. Physical models were established.Error analysis in the process of high-speed photography was carried out.